1. Field of the Invention
The present invention relates to an expression detecting system, an expression detecting method and a program. Specifically, the present invention relates to an expression detecting system, an expression detecting method and a program for detecting an expression describing an evaluation of a specific object from a text describing the evaluation of said specific object.
2. Background Art
In developing a new product or a new service, it has become more and more important to catch up with consumers' preference (likes and dislikes) correctly and set the preference that appear to start a trend as a basic concept of the development. For example, a brewery developed their new brand of beer with an explicit concept of “dry” in mid-1980s. The product made a hit and brought the company to the top of the industry. As such, how correctly a company notices an expression including appropriate preference will determine the future of the company.
Generally, individual preference varies with an attribute of a group, such as a generation or a region as well as time. Therefore, it is important to periodically monitor individual preference, immediately notice a change in the trend and make best use of the change in developing a new product or service. In the conventional arts, however, stereotyped data such as questionnaire items or a purchase history is used for analyzing the trend (see Published Unexamined Patent Application No. 2003-203136 and Published Unexamined Patent Application No. 2000-293526)
Stereotyped data such as questionnaire items only yields evaluations selected from predetermined choices made by those who made the questionnaire or responses to questions made by those who made the questionnaire. In order to solve this problem, a technique for analyzing evaluations of a product or the like based on a normal sentence as well as on stereotyped data such as a questionnaire is proposed (see Published Unexamined Patent Application No. 2002-297626, Published Unexamined Patent Application No. 2003-248681, and Published Unexamined Patent Application No. 2002-140465.
The technique disclosed in Published Unexamined Patent Application No. 2002-297626 intends to learn individual preference (likes and dislikes) for an advertisement on the basis of non-stereotyped text data written on the advertisement. This technique uses a preference expression rules dictionary to extract likes and dislikes. For this reason, it is assumed that a user manually records keywords relating to preference in the dictionary beforehand. In the technique disclosed in Published Unexamined Patent Application No. 2003-248681, an affect term included in an expression indicating an emotion is recorded in a dictionary beforehand an expression including the affect term is detected as an expression indicating the emotion. For this reason, any expression that is not assumed cannot be detected as an expression indicating an emotion.
Published Unexamined Patent Application No. 2002-140465 discloses a technique for determining whether a keyword detected from text data indicates a favorable (affirmative) opinion about the object or not. This technique prepares a database that has registered whether each of the keywords indicates a favorable opinion or not, and determines whether a keyword detected from text data is registered in the database or not.
In such conventional arts, it is assumed that the expression which appears in text data is already recorded in database to enable determination of whether or not the expression indicates individual preference. For this reason, it is difficult to find a new expression indicating individual preference and apply the expression to marketing.